Premature infants are at risk for a variety of developmental problems including delays in language development, perceptual processing and social interaction. The goal of this mentored research is to examine the development of interactive communication in preterm infants so that interventions can be designed to improve their abilities. The educational aims of the research are to refine skills in observing interactive communications, including behavioral coding of discrete qualities of communication and sequential analysis of social interaction, and to develop a coding schema for future intervention research. The purpose of the study is to observe interactions between premature infants and their mothers to describe patterns of communication over the first 4 months of life, and to compare their interactive communication abilities to those of term infants and their mothers. The sample will include 20 preterm infant-mother pairs and 20 full term infant-mother pairs. One hour videotaped observations will be made on three occasions for the preterm group (36 weeks gestation, 41 weeks corrected age, and at 4 months corrected age) and on 2 occasions for the term group (at 1 week and 4 months of age). The aims are to describe the development of vocal and nonvocal exchanges in premature infants, determine the effect of neurological insults and gestation on these patterns, and to compare preterm and term infant patterns of interactive communication. Observational behavioral coding will be used to determine the quality, frequency, duration and sequence of vocal and non vocal behavior of mothers and infants. Sequential analysis of the observed interactions will be conducted and conditional and transitional probabilities calculated. The two groups will be compared with repeated measures MANOVA and the mixed general linear model on selected behavioral responses and vocalizations.